1. Field of the Invention
The invention relates to a cap with fluid seal, to a process for making such a cap and, finally, to an assembly comprising a container for certain contents and the cap with fluid seal in question.
2. The Related Art
Caps made of sufficiently rigid plastics material are already known, of the type comprising, on the one hand, a transverse wall and an adjoining annular skirt internally provided with screw threads and, on the other hand, an inner annular projection projecting from the inner face of the skirt in the vicinity of the transverse wall. It is known that such a projection may have the function of participating in the maintenance of a fluid seal.
Fluid seals made of plastics material capable of being elastically deformed are also known, of the type comprising, on the one hand, an elastically deformable peripheral bead and, on the other hand, a transverse wall on the periphery of which the bead is located. Such a fluid seal may form part of a cap being maintained by means of the inner annular projection with which the latter is provideed. In such an embodiment, the peripheral bead of the seal may cooperate with the edge of the neck of the container in order to ensure a tight closure.
Moreover, caps such as those mentioned hereinabove are known, which further comprise a tamperproof ring adjoining the free edge of the skirt opposite the transverse wall, the connection between the skirt and the tamperproof ring being of lesser resistance in order to be able to be fractured when the cap is first opened, the tamperproof ring further comprising, towards the inside, means adapted to interfere with a corresponding annular projection provided on the neck of the container.
Reference may be made in particular to documents EP-A-637 550, GB-A-2 092 999, WO-A-94-18084, FR-A-2 709 473, FR-A-2 692 555, FR-A-2 711 969 and, finally, FR-A-2 454 568.
Generally, the sealing means that the caps comprise belong to one of the following three families:
the one where the sealing means are integrated in the cap itself, designed accordingly;
the one where the fluid seal is made in situ, in the cap itself;
and, finally, the one where the fluid seal made previously elsewhere, is added in the cap.
The invention concerns this third and last family and not the first two, which have their specificities and their own constraints. An example of cap belonging to this third family is known from FR-A-2 721 677 which discloses a cap comprising a fluid seal mounted floating and provided with an annular boss which maintains its transverse wall at a distance form the bottom of the cap.
Consequently, the invention aims at producing a cap with added fluid seal in which the seal is made efficiently while the positioning of the cap, in added manner, is effected conveniently.
More particularly, the invention aims at producing a cap with added seal moulded shouldered but floating, as is described.
Furthermore, the invention aims at a plurality of maximum embodiment with considerable suppleness and facility of implementation.
In effect, a seal as provided here may be mounted on different types of cap shells whose internal shape is adapted. Furthermore, these shells may, depending on the cases, receive an added seal as described or a seal made in situ.
According to a first aspect, the invention relates to a cap with fluid seal, in which:
the cap proper, made of sufficiently rigid plastics material, comprises, on the one hand, a transverse wall and an adjoining annular cylindrical skirt provided internally with screw threads intended to cooperate with complementary screw threads on the neck of a container, on the other hand, an internal annular projection projecting from the inner face of the skirt in the vicinity of the transverse wall, this projection having the function of participating in the maintenance of a fluid seal;
the fluid seal, made of plastics material capable of being elastically deformed, comprises in the first place an elastically deformable peripheral bead with which the edge of the neck of the container can cooperate for the seal, in the second place a transverse wall on the periphery of which the bead is located, and in the third place a supple annular shoulder for maintaining the seal, cooperating with the annular projection of the cap proper;
the fluid seal, when it is made, is added in the cap and maintained floating by means of the inner annular projection cooperating with the shoulder so that there is formed between the inner face of the transverse wall of the cap and the opposite face of the fluid seal a space of generally flattened cylindrical shape in which the seal may be housed once the cap with fluid seal is mounted and tightened on the neck of the container.
At rest, the fluid seal is limited on the side of the transverse wall of the cap by a substantially planar face. The bead projects on the side of the opposite face of the seal which is intended to face towards the neck of the container. The supple annular shoulder outwardly surrounds the bead and is disposed in line with the transverse wall of the seal. This shoulder is intended to cooperate with the inner annular projection of the cap in order to ensure maintenance of the fluid seal, the latter thus being maintained in shouldered and floating manner. This shoulder presents a suppleness and an axial thickness adapted to allow easy assembly with a view to efficient maintenance of the seal in the cap proper.
When the fluid seal is mounted in the cap and at rest, the face or the projecting free edge of the bead opposite the transverse face of the seal is disposed substantially in the plane of the face or the projecting free edge of the inner annular projection of the cap.
The space between the cap and the fluid seal is such that it is adapted, on the one hand, to allow the appropriate deformation of the fluid seal further to the assembly and tightening of the cap provided with the seal on the neck of the container. On the other hand, this space is adapted to allow the application and abutment of the seal against the inner face of the cap, once the latter is mounted and tightened on the neck of the container.
The bead presents, in traverse cross section, a profile generally in the form of a V or a U, or W or pseudo Vxe2x80x94in particular with truncated or rounded apexxe2x80x94, or pseudo U, or pseudo W.
In one embodiment, the bead is outwardly limited by a substantially truncated or cylindrical face corresponding substantially to the narrowed opening formed by the inner projection of the cap. The bead is inwardly limited by a substantially truncated face of which the diameter nearest the transverse wall of the seal is the small diameter while the large diameter is intended to face towards the neck of the container.
According to to one embodiment, the fluid seal also comprises a second annular bead placed inside the first and slightly spaced apart therefrom radially.
The inner projection of the cap presents, in transverse cross section, the general shape of a V, or a U, or a pseudo Vxe2x80x94particularly with truncated apexxe2x80x94, or pseudo U, upturned, comprising an arm substantially transverse with respect to the principal axis of the cap and an arm slightly inclined on this axis.
According to an embodiment, the cap, with fluid seal which has just been described, further comprises a tamperproof ring adjoining the free edge of the skirt opposite the transverse wall. The connection between the skirt and the tamperproof ringxe2x80x94by bridges, cut-outs, a smaller thickness or otherxe2x80x94is of lesser resistance in order to be able to be fractured when the cap is first opened. In addition, the tamperproof ring inwardly comprises projecting means adapted to interfere with a corresponding annular projection provided on the neck of the container. These projecting means are, according to their embodiments, a bead, one or more tabs, one or more projections or otherwise.
Such a cap with fluid seal and tamperproof ring may form the subject matter of different variant embodiments. According to a first variant, the tamperproof ring itself is transversely breakable at at least one place and opens when the cap is first opened. According to another variant, the ring is not transversely breakable.
When the ring is breakable, it may be connected to the skirt by at least one non-frangible connection or, on the contrary, may not comprise such a non-frangible connection.
According to another aspect, the invention relates to a process for producing a cap as has just been described. In this process, the cap and the fluid seal are firstly made separately by injection, compression or otherwise. Then the fluid seal is positioned and associated in and with the cap, forcing the seal to pass beyond the inner projection of the cap. This operation is rendered possible further to the shape and constitution of the shoulder combined with the shape of the cap proper. The seal is then maintained shouldered but floating in the cap.
According to a last aspect, the invention concerns an assembly comprising, on the one hand, a container for certain contents, this container being provided with a neck with an outer threading and, as the case may be, with an annular projection intended to cooperate with a tamperproof ring. The assembly comprises, on the other hand, a cap with fluid seal as has just been described. This cap with seal is mounted and tightened on the neck of the container. With respect to the situation where it is at rest, the fluid seal is deformed in order to be applied in abutment on the inner face of the cap, the bead being crushed and deformed by the free end part of the neck of the container.